Hi Fi, what does this mean ?

Quigs Snr

Thinking of buying a Sony CMTGP7 Micro HiFi, with MP3 from peats online (238 including delivery).


Anyway, it's specs are 100W RMS (10% THD). What does the THD thing mean ?

Is 100w RMS (I assume it's 50W per speaker) is plenty loud enough for my living room ??

Sleipnir

I came across that term before, I *think* it means "total harmonic distortion"

Kali

aye it stands for total harmonic distortion.. harmonics are very basically copies of the original soundwave repeated at higher frequencies (and at a much lower amplitude (read: volume)).. the THD figures are got by feeding an amplifier (or any component in fact) a pure-formed soundwave (typically a sine wave) and checking what % of the output is composed of these harmonics... anyway 10% is quite bad... for high-end equipment its commonly less than 1%... a figure that large would be easily noticeable with headphones... less so with speakers.

silverside

Yes its "total harmonic distortion"
most ratings for 'proper' hi-fi are done at something like 1% THD.

Basically the higher you crank up the power, the more the amp distorts, this becomes audible and spoils the sound. The harmonics are multiples of the original frequency so if the originl signal is say 1000 Hz, the harmonics come in as spurious signals of 2000, 3000, 4000 Hz.

Sony are using the 10% level as a way of exagerrating the power of the system, at 1% THD it would have a lower power rating.

But I would never buy audio equipment without listening to it first. Can you not pop in to Peats/Power City at the weekend and listen to a few systems, Sony are a big name but all audio quality is variable and subjective.

^whitey^

100W RMS is plenty loud enugh for your living room for just listening to music, but if your going to be listening to music at a high volume most of the time maybe think about getting something else.

However if your not going to be listening to music at high volume it seems fine but IMO the price is a bit steep for what your getting. Having said that i'm too lazy to google around to prove my point.

robbie1876

Very well explained, silverside. Sony are indeed being coy about their ratings. As has been stated too, it's all irrelevant too, you have to listen to the equipment. The specs don't tell you how good or bad it sounds, it's as simple as that.

Robbie